SchizocoelySchizocoely (adjective forms: schizocoelous or schizocoelic) is a process by which some animal embryos develop. The schizocoely mechanism occurs when secondary body cavities (coeloms) are formed by splitting a solid mass of mesodermal embryonic tissue. All schizocoelomates are protostomians and they show holoblastic, spiral, determinate cleavage. The term schizocoely derives from the Ancient Greek words σχίζω (), meaning 'to split', and κοιλία (), meaning 'cavity'.
GastrulationGastrulation is the stage in the early embryonic development of most animals, during which the blastula (a single-layered hollow sphere of cells), or in mammals the blastocyst is reorganized into a multilayered structure known as the gastrula. Before gastrulation, the embryo is a continuous epithelial sheet of cells; by the end of gastrulation, the embryo has begun differentiation to establish distinct cell lineages, set up the basic axes of the body (e.g.
NotochordIn anatomy, the notochord is a flexible rod which is similar in structure to the stiffer cartilage. If a species has a notochord at any stage of its life cycle (along with 4 other features), it is, by definition, a chordate. The notochord consists of inner, vacuolated cells covered by fibrous and elastic sheaths, lies along the anteroposterior axis (front to back), is usually closer to the dorsal than the ventral surface of the embryo, and is composed of cells derived from the mesoderm.
Frameshift mutationA frameshift mutation (also called a framing error or a reading frame shift) is a genetic mutation caused by indels (insertions or deletions) of a number of nucleotides in a DNA sequence that is not divisible by three. Due to the triplet nature of gene expression by codons, the insertion or deletion can change the reading frame (the grouping of the codons), resulting in a completely different translation from the original. The earlier in the sequence the deletion or insertion occurs, the more altered the protein.
TubuleIn biology, a tubule is a general term referring to small tube or similar type of structure. Specifically, tubule can refer to: a small tube or fistular structure a minute tube lined with glandular epithelium any hollow cylindrical body structure a minute canal found in various structures or organs of the body a slender elongated anatomical channel a minute tube, especially as an anatomical structure.
Chronic kidney diseaseChronic kidney disease (CKD) is a type of kidney disease in which a gradual loss of kidney function occurs over a period of months to years. Initially generally no symptoms are seen, but later symptoms may include leg swelling, feeling tired, vomiting, loss of appetite, and confusion. Complications can relate to hormonal dysfunction of the kidneys and include (in chronological order) high blood pressure (often related to activation of the renin–angiotensin system system), bone disease, and anemia.
Nonsense mutationIn genetics, a nonsense mutation is a point mutation in a sequence of DNA that results in a premature stop codon, or a nonsense codon in the transcribed mRNA, and in leading to a truncated, incomplete, and nonfunctional protein product. Nonsense mutation is not always harmful, the functional effect of a nonsense mutation depends on many aspects, such as the location of the stop codon within the coding DNA. For example, the effect of a nonsense mutation depends on the proximity of the nonsense mutation to the original stop codon, and the degree to which functional subdomains of the protein are affected.
EnterocoelyEnterocoelom (adjective forms: enterocoelic and enterocoelous) describes both the process by which some animal embryos develop and the origin of the cells involved. In enterocoely, a mesoderm (middle layer) is formed in a developing embryo, in which the coelom appears from pouches growing and separating from the digestive tract (also known as the embryonic gut, or archenteron). As the incipient coelomic epithelium originates from archenteral diverticula, the endoderm therefore gives rise to the mesodermal cells.
NephronThe nephron is the minute or microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and a cup-shaped structure called Bowman's capsule. The renal tubule extends from the capsule. The capsule and tubule are connected and are composed of epithelial cells with a lumen. A healthy adult has 1 to 1.5 million nephrons in each kidney.
Distal convoluted tubuleThe distal convoluted tubule (DCT) is a portion of kidney nephron between the loop of Henle and the collecting tubule. It is partly responsible for the regulation of potassium, sodium, calcium, and pH. On its apical surface (lumen side), cells of the DCT have a thiazide-sensitive Na-Cl cotransporter and are permeable to Ca, via the TRPV5 channel. On the basolateral surface (peritubular capillary side) there is an ATP-dependent Na/K antiporter pump, a secondary active Na/Ca transporter, and an ATP dependent Ca transporter.
